NAPERVILLE, Ill. (CBS) — Naperville police are looking for the thieves who are have stolen four manhole covers right out of the street.

Naperville Crime Stoppers is offering a $1,000 cash reward for information leading to the thief or thieves. They stole four sewer and water manhole covers that belong to the City of Naperville in the past few weeks, Naperville police said.

The covers weigh about 50 pounds each, and are stamped “sanitary” sewer or “water,” police say.

The thefts happened in the southwest section of Naperville where new subdivisions are under construction. With manholes now sitting open due to the thefts, police caution anyone driving or walking through new-construction subdivisions.

Police Sgt. Gregg Bell said no one has been injured or fallen into an open manhole so far.

Anyone with information is asked to call Crime Stoppers at (630) 420-6006. Anyone who calls may remain anonymous.